The investigation of biliprotein structure and function has been focused on studies using black lipid membranes containing chlorophyll and carotenoid. Recent experiments with this model membrane system have demonstrated that phycocyanin acts to direct electron transfer across chloroplast extract membranes. Additional studies are planned to investigate the effect of other biliproteins on electron flow in this system, as well as the effect of the state of aggregation of the biliprotein on this property. The effect of specific lipid content, pH and redox couple factors on membrane properties will be elucidated. Eventually, other parts of the electron transfer chain in photophosphorylation will be examined in this system. Correlated studies on methods to stimulate the formation of large phycocyanin aggregates for membrane work will be pursued. The interaction of phycocyanin, phycoerythrin, allophycocyanin and chlorophyll in solution will also be investigated for the determination of conditions that would permit maximal energy transfer and electron flow in the model membrane system. The elucidation of energy transduction and electron transfer in the model membrane system would assist in our efforts to understand the reduced efficiency of the electron transfer process across membranes in cells that have impaired function due to infections or genetic disorders. BIBLIOGRAPHIC REFERENCES: Berns, D. S. (1976) Photosensitive Bilayer Membranes as Model Systems for Photobiological Processes. Photochem. Photobiol. 24, 117-139. Chen, C-H. and Berns, D.S. (1976) Photosensitivity of Artificial Bilayer Membranes: Lipid-Chlorophyll Interaction. Photochem. Photobiol. 24, 255-260.